Posted at January 6, 2014 4:59 pm by Diane O'Leary, PhD at NORD Rare Disease Dialog Blog
It can be disheartening for rare disease patients to consider the problem of diagnostic delay. As NORD’s recent informal survey revealed, more than half of us spend three years or more looking for diagnosis and treatment. Once we find it, it’s natural to want to put the whole problem behind us.
The good news is that facing the problem doesn’t have to lead us to hopelessness because there is actually something we can do about it. When we take a hard look, we find reason to be optimistic about what we can do simply by raising awareness.
What Causes the Delay?
For the most part, rare diseases are unfamiliar to doctors. There are almost 7,000 of them, and that’s just too many for any doctor to hold in the working memory bank. How could we ever fix something like that?
There are two ways. First, the information age has produced searchable databases of rare diseases, and FDA-approved devices and apps that doctors can pull from their pockets when they’ve exhausted their diagnostic instincts. The problem of access to information really has been resolved.
What remains is the task of bringing doctors to recognize the need to use this information. Imagine a world where every rare disease patient shared the same clear mark — something like Harry Potter’s lightening-bolt birthmark. In a world like that, the problem of diagnostic delay would dissolve. When diagnosis got tough, doctors would find the mark, pull the smart phone from the pocket, and start plugging in symptoms. Problem solved.
Most of us were stunned when NORD first let us know we’re “1 in 10″ a few years ago, and anyone who’s offered that figure to friends has known to expect the surprise. Ten percent of Americans have rare diseases? There’s good reason to think our doctors would be as astonished to hear that as we were.
Doctors-in-training are still taught to concentrate their diagnostic efforts on common diseases rather than rare ones. The medical school adage, “When you hear hoof beats, think horses, not zebras”, still typifies diagnostic protocol and this is a direct obstacle to rare disease diagnosis and treatment.
How Many Zebras Are There?
It’s the size of the problem that’s eluding our doctors. The number of people with rare disease is roughly the same as the number with asthma. There are almost 30 million of us — one on every crowded elevator, four on every full bus. We are roughly equal to the population of Canada.
There are six times as many rare disease patients as there are patients with Alzheimer’s. For every person with HIV or AIDS, there are 30 people with rare disease, but this is the most telling statistic by far: rare disease patients outnumber cancer patients 2 to 1.
There are so many rare disease patients that the average doctor sees at least two to three on every working day. They are as common as diabetics. How is it, then, that diabetes has been declared “epidemic”, while rare disease is so far off the radar that doctors are actually trained to ignore it as a diagnostic possibility?
Addressing Lack of Awareness
Anyone who’s experienced the problem of diagnostic delay first-hand knows its source. In the doctor’s world, the phrase “medically unexplained symptoms” has actually been defined: It means “symptoms with psychiatric causes”. These labels are essentially interchangeable in practice.
When doctors are unable to explain patients’ symptoms — as they are for at least three years in the majority of rare disease cases — psychiatric diagnosis is made by default.
That is the heart of the problem. Doctors don’t recognize the need to use that database of diseases because they’ve been trained to believe unexplained symptoms need no further investigation: They always have psychiatric causes.
In the current International Classification of Diseases, the category of medical problems with psychiatric causes is defined with this:
“The main feature is repeated presentation of physical symptoms together with persistent requests for medical investigations, in spite of repeated negative findings and reassurances by doctors that the symptoms have no physical basis.”
Unnerving as it is to recognize how pervasive this problem is, it is one we can fix. The mark of a rare disease patient needs to be distinguished in practice from the mark of a patient whose symptoms have psychiatric causes.
If the World Health Organization recognized that this definition applies in error to the majority of rare disease patients, revision efforts for the new edition would have to focus on fixing that problem. If they understood how this approach obstructs treatment for a patient population twice the size of all cancer patients, they’d hone their revisions to protect that population.
If doctors around the globe were trained not to ignore the zebras, but to expect to find at least one in every tenth hospital bed, that adage would be seen in its true light. Diagnostic protocols would radically change. Young doctors would not be criticized for needing that database of diseases — they’d be criticized for not making use of it a few times each day.
The problem of diagnostic delay for rare disease patients is one every doctor should be made aware of. Our numbers speak for themselves, and spreading awareness of that fact is the greatest gift we can give to our children and our children’s children.
Diane O’Leary PhD is Executive Director of The Sneddon’s Foundation.